Jaw crusher



p 1970 A. N. MAURER 3,527,420

Filed July 12, 1968 A. N. MAURER Sept. 8, 1910 JAW CRUSHER 2 Sheets-Sheet 2 Filed July 12, 1968 INVENTOR ARCHIE u. URER ATTORNEY United States Patent US. Cl. 241-217 Claims ABSTRACT OF THE DISCLOSURE The crushing surface of jaw dies of the present design are formed with two sets of teeth which are substantially parallel and which extend from top to bottom of the die. A set of first or coarse teeth extend along a curved path in a center zone of the die and thereafter are formed so as to gradually increase in height as they extend from this center zone to the adjacent top and bottom zones of the die. A set of second or fine teeth extend from the top to the bottom of the die along a curved path. This crushing surface design provides jaw dies which are reversible, have a relatively uniform wear characteristic, have a relatively high crushing capacity, and prevent slabs of material from falling uncrushed through the crushing chamber of a jaw crusher.

BACKGROUND OF THE INVENTION The jaws in a jaw crusher are generally provided with replaceable jaw dies that contact and exert a crushing force on the rock or other material that is being crushed. The crushing surface of these jaw dies are conventionally formed with a series of parallel teeth which are arranged on the jaw such that the teeth extend in a substantially vertical direction through the crushing area. The size, shape, and pitch of the teeth on a jaw die, as well as the surface contour of the jaw die, determine to a great extent the ultimate effectiveness of the crusher, the uniformity of jaw die wear and the uniformity of the resulting crushed products. Thus, these factors are frequently varied in order to solve particular crushing problems.

For example, the output of a jaw crusher is frequently limited by the fact that the major portion of the final crushing occurs in a very narrow crushing zone adjacent the lower or exit opening of the movable jaws. In addition, this narrow crushing zone naturally tends to wear more rapidly than the remaining areas of the jaw die face and results in a jaw die having a relatively short effective life. These problems have partially been solved by having the teeth of the jaw dies extend down the cnlshing surface thereof in a circumferential path of a large diameter circle and by designing the jaws such that the faces of the opposed jaw dies in the lower or final crushing zone are slightly spaced apart and nearly parallel when the jaws have been brought as close together as possible in their crushing position. Still, however, the problems remain of even further increasing the maximum output capacity of any given size jaw crusher and at the same time decreasing the wear rate of the crushing surface on the jaw die. In addition, the above described conventional jaw dies have a basic defect in that they sometimes permit thin slabs of materials to slide through the crushing chamber without being crushed.

SUMMARY OF THE INVENTION The jaw die design of the present invention seeks to correct these problems through the particular design of the jaw die teeth on the crushing surface. In particular, a coarse set of the teeth, in addition to the normal fine set of teeth, are formed on the crushing surface of the jaw die. The fine teeth extend from top to bottom of the die along a circumferential path of a large diameter circle, as in a conventional jaw die. The coarse teeth, on the other hand, extend along a similar circumferential path only at a center portion of the die and the teeth are formed to gradually increase in height as they extend from this center section to the top and bottom of the die. It has been found that jaw dies having this type of arrangement of teeth have a greater maximum output capacity than the equivalent jaw die described above and that this dual tooth arrangement yields a relatively uniform wear characteristic across the face of the die.

Finally, the jaw dies are made symmetrical about a horizontal plane through the center of the jaw die so that the dies may be turned around or reversed on the jaw support and in this manner the wear of the jaw die may be more evenly distributed over the entire jaw die surface.

Accordingly, one object of the present invention is to provide jaw dies for jaw crushers having faces shaped to secure a more even wear characteristic across the face of the jaw die.

A second object is to provide reversible jaw dies having crushing surfaces designed to prevent slabs of material from sliding uncrushed through a jaw crusher.

Another object is to provide the crushing surface of a jaw die with at least two sets of teeth which are formed in such a manner that the wear characteristic of the crushing surface is improved.

Still another object of the invention is to provide jaw dies for crushers having faces shaped so as to enable more exact sizing of crushed material and to enable a higher output capacity of such crushed material.

A further object is to provide a jaw crusher having jaw dies with crushing surfaces designed to increase output capacity, decrease the wear rate of the crushing surfaces and which prevents slabs of material from sliding uncrushed through the crushing chamber.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, advantages and novel features of the present invention will become apparent in the following description of the invention when considered in conjunction with the drawings wherein:

FIG. 1 is a side view of the interior of a jaw crusher illustrating the jaw dies of the present invention mounted on the crusher jaws;

FIG. 2 is an enlarged vertical cross sectional view through the jaws shown in FIG. 1 and taken in a plane parallel with the plane of the drawing;

FIG. 3 is a view taken along line 33 of FIG. 2;

FIG. 4 is a bottom view of the jaw die shown in FIG. 3;

FIG. 5 is a view taken along line 55 of FIG. 2;

FIG. 6 is a bottom view of the jaw die shown in FIG. 5;

FIG. 7 is a view taken along line 7-7 of FIG. 2.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. 1, it will be noted that the jaw dies of the present invention are shown employed, for example, on a jaw crusher 10 having one fixed jaw 12 and one movable jaw 14. The two jaws oppose each other and are arranged so that they incline downwardly toward each other so as to define a crushing chamber 19 having a relatively wide upper inlet opening 20 and a relatively narrow lower outlet opening 22. The jaw dies 24, 26 of the present invention, which are preferably made of a wear resistant material such as manganese steel, and are mounted on the front face of each jaw by coupling means well known in the art. In the crusher shown in FIG. 1, the coupling is accomplished by means of jaw die extensions 28, 30, which serve to hold the jaw dies in wedging engagement with the lower lips formed on the bottom of the jaws. The movable jaw 14 is activated by an eccentric shaft 34 which is rotatably mounted in the top section of the movable jaw body and which shaft is rotatably driven by a motor not shown. Coupled to the bottom section of the movable jaw is toggle mechanism 38, and a tension rod mechanism 40, which are well known in the art. In operation, the movable jaw is actuated back and forth in a substantially elliptical path. Bulk material that is to be crushed is deposited into the inlet opening 20 of the crushing chamber from any conventional material conveying means such as, for example, a vibrating conveyor V. The material is crushed by the reciprocating action of the movable jaw as the material falls between the jaw dies and the crushed material finally exits through opening 22 at the bottom of the jaws.

The jaw dies, as seen in FIG. 3, are substantially rectangular with a top 24a, bottom 24b, and two sides 24c, 24d. As seen in FIG. 2, the rear face is formed with a flat surface 24e for abutting against the front of the jaw and the front face or crushing surface 24 has a generally curved contour extending from top to bottom of the die. Formed on the crushing surface 24 are a series of substantially parallel teeth 44, 46, which extend in a generally vertical direction from the bottom to the top of the die or, in other words, when the jaw die is in operable position on the jaws of a jaw crusher the teeth extend in the general direction of movement of material falling through the crushing chamber of the machine. Both jaw dies have similar size and shape teeth and only the arrangement of the teeth on the crushing surface are staggered in the manner hereinafter described.

As shown in FIG. 3, the jaw die 24 has fine pitch teeth 44 and coarse pitch teeth 46. For purposes of definition, any two immediately adjacent teeth of the same type are called a set of teeth; the transverse distance between the crests of these immediately adjacent teeth is called the pitch or the pitch distance and the use of the words fine or coarse together with the above defined terms indicates whether these terms apply to fine teeth 44 or coarse teeth 46. As shown in FIG. 7, the fine pitch p is one-third the coarse pitch cp and a set of fine pitch teeth are positioned between each set of coarse pitch teeth, as shown in FIGS. 4 and 6, so that the transverse distance between the crests of any two adjacent teeth are equal to the fine pitch fp. This arrangement of teeth is repeated across the crushing surface of the jaw die. A similar arrangement of fine pitch teeth 48 and coarse pitch teeth 50 are formed on the front face of jaw die 26, however, these are staggered or offset a distance equal to one half the coarse pitch distance. In this manner, when the jaw dies are coupled onto the jaws of a jaw crusher, the teeth on the opposed jaw dies would tend to intermesh, if brought together, with the crests of the coarse teeth on one die fitting between two adjacent fine teeth on the opposed die.

A vertical section through a jaw die from top to bottom, as in FIG. 2, illustrates the longitudinally extending crest lines and base lines for both types of teeth and further reveals the three crushing surface zones a, b, and 0. Zone b is the center crushing surface zone of the jaw die and zones a and c are referred to simply as the adjacent crushing surface zones in order to signify that they are immediately adjacent this center zone. It also should be noted, however, that when the dies are mounted in operable position on the jaws of the jaw crusher, as shown in FIGS. 1 and 2, zones a and c may be referred to as the lower zone and the upper zone, respectively. The crest line and the base line of the fine pitch teeth extend between the top and bottom of the jaw die in a curved or circumferential path of a large diameter circle and the height of these teeth are substantially uniform throughout. The crest line of the coarse pitch teeth extends from the top to the bottom of the jaw die along a straight line path in zone c, along a curved path in middle zone b, and along a straight line path again in the zone 0. The base line of the coarse teeth follows a curved path similar to th path followed by the base i e f he fine teeth. The radius of cuvature of the curved path described by-the crest lines for the coarse teeth in the middle zone is the same as for the curved path defined by the crest lines of the fine teeth. Furthermore, in the middle zone b, both the fine and coarse teeth are of substantially the same height and serve substantially the same intermediate crushing function. The crest lines of the coarse teeth proceed from the middle zone into each of the adjacent zones on straight paths which are substantially tangent to the curved path defined by the crest lines of the coarse teeth in the center zone. In this manner, the height of the coarse pitch teeth is gradually increased as the teeth extend from the center zone through each of the adjacent zones a, c.

The zones a and c are substantially the same size and the crushing surface is formed symmetrically about an imaginary horizontal cross sectional plane taken through the center zone of the jaw die. In this manner, it is possible to reverse the jaw dies on the jaws of the crusher so that the top 24a would be positioned at the bottom of the jaw and so that crushing surface zone 0 indicated in FIG. 2 would then become the lower zone in the crushing chamber.

It will be apparent that when the jaw dies of the present invention are mounted on the jaws of a jaw crusher, the fine teeth with crest lines 44a, 48a, in the lower zone a, as seen in FIG. 2, are substantially parallel and this enables material crushed in this last zone to be substantially uniform in size and provides a large final crushing zone. Thus, a relatively high output capacity from the jaw crusher may be obtained. Furthermore, the coarse teeth in the lower zone a serve a slab-breaking function by virtue of the fact that the gradually increased height of the coarse teeth permits these teeth to extend outward toward the teeth on the opposed jaw die and thereby having the coarse teeth extend across the lower opening of the crushing chamber. Thus, slabs of material are crushed by these teeth which might otherwise fall uncrushed through the space between the crests of the fine teeth on opposed jaw dies. Finally, it will be noted that the crush ing surface is symmetrical about an imaginary horizontal plane taken through the center of the jaw die and that the die can, therefore, be easily reversed so as to increase the life of the crushing surface and to achieve a more uniform wear rate of the crushing surface.

When the jaws of a crusher, having the jaw dies of the present invention mounted thereon, are operated, it will be apparent that large material falling into the upper zone c will initially be crushed by the coarse pitch teeth. In this manner, the fine teeth in this upper zone will not be used for much of the crushing that will normally take place in this zone. As the material to be crushed falls into the middle zone b, all the teeth are substantially the same and perform the same type of intermediate crushing. In the lower zone, the fine teeth and coarse teeth combine to crush the material to final size while the coarse teeth also serve to prevent any slabs of rock from falling between the jaws without being crushed. It is this arrangement which tends to prevent excessive wear of the fine teeth in the upper zone. Thus, when the jaw dies are reversed, the fine teeth now in the lower crushing zone are relatively unworn and capable of more extensive use. The combination of these two types of teeth on the crushing surface of a jaw die has increased the life of the jaw die by decreasing the wear rate and at the same time has enabled jaw crushers to achieve higher output capacities of crushed products.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A jaw die for jaw crushers, said jaw die having a crushing surface comprising at least one set of first teeth and one set of second teeth formed thereon, both of said sets of teeth being substantially parallel to each other and extending from a center crushing surface zone to adjacent crushing surface zones on each side of said center zone, said set of first teeth being of substantially uniform height in said center zone and having crest lines which describe a curved path in said center zone, said set of first teeth gradually increasing in height as they extend from said center zone into each of said adjacent zones, said set of second teeth having crest lines which describe a curved path in said center zone and in each of said adjacent zones.

2. A jaw die as described in claim 1 wherein said set of first teeth comprises two teeth spaced from each other a distance equal to the coarse pitch distance, and said set of second teeth having two teeth with crest lines spaced from each other a distance equal to a fine pitch distance and which fine pitch distance is substantially equal to one third the coarse pitch distance, said set of second teeth being positioned between said set of first teeth such that the transverse distance between the crest lines of any two successive teeth on said crushing surface is equal to the fine pitch distance.

3. A jaw die as described in claim 2 wherein said crushing surface is further defined by the radius of curvature of the curved path described by the crest lines of said set of second teeth being equal to the radius of curvature of the curved path described in said center zone by the crest lines of said set of first teeth.

4. A jaw die as described in claim 1 wherein crest lines of said set of first teeth are straight lines in each of said adjacent zones.

5. A jaw die as described in claim 4 wherein the crest lines of said set of first teeth in said adjacent zones are tangent to the curved path defined by the crest lines of said set of first teeth in said center zone.

6. In a crusher having relatively movable jaws, a removable jaw die mounted on each jaw, each of said jaw dies having a crushing surface, each of said crushing surfaces having a center zone and an adjacent zone on either side of said center zone and further comprising at least one set of coarse teeth and one set of fine teeth formed thereon, both of said sets of teeth extending in the general direction of movement of material through said crusher, said set of coarse teeth having a coarse pitch, said coarse teeth extending through said center zone at a substantially uniform height and with the crest line of said coarse teeth extending in a curved path, said coarse teeth gradually increasing in height as they extend from said center zone into said adjacent zones, said set of fine teeth having a fine pitch, said fine teeth extend- Cal ing through said center and said adjacent zones at a substantially uniform height and with the crest lines of said fine teeth defining a curved path.

7. In a jaw crusher having jaw dies with crushing surfaces as described in claim 6 and which crushing surfaces are further described by said set of coarse teeth having two teeth spaced from each other a distance equal to the coarse pitch, said set of fine teeth having two teeth spaced from each other a distance equal to the fine pitch and which fine pitch is substantially equal to one third the coarse pitch, said set of fine teeth being positioned between said set of coarse teeth such that the transverse distance between the crest lines of any two adjacent teeth on the crushing surface of a jaw die is equal to the fine pitch.

8. In the jaw crusher having jaw dies with crushing surfaces as described in claim 7 and which crushing surfaces are further described by the radius of curvature of the curved path described by the crest lines of said set of fine teeth being equal to the radius of curvature of the curved path described in said center zone by the crest lines of said set of coarse teeth.

9. In the jaw crusher having jaw dies with crushing surfaces as described in claim 6 and which crushing surfaces are further defined by each of said jaw dies being symmetrical about a horizontal cross sectional plane through the center of said jaw dies.

10. In the jaw crusher having jaw dies with crushing surfaces as described in claim 9 and which jaw crusher is further characterized by said jaw dies opposing each other so as to define a crushing chamber having an inlet opening and an outlet opening, said coarse teeth extending into said outlet opening whereby slabs of material are prevented from sliding uncrushed through said crushing chamber.

References Cited UNITED STATES PATENTS 83 8,921 12/1906 Velten 241-217 X 3,144,214 8/1964 Perdue 24l-291 FOREIGN PATENTS 149,838 3/1904 Germany. 945,546 6/ 1956 Germany.

LESTER M. SWINGLE, Primary Examiner D. G. KELLY, Assistant Examiner US. Cl. X.R. 24l291 

